Electrical circuit control switch



Dec. .5, 1961 o. 1. PRICE, sR

ELECTRICAL CIRCUIT CONTROL SWITCH 3 Sheets-Sheet 2 Filed July 10, 1959 INVENTOR 60. moms in haw/M51. PR/C'f; z 058 05 N: I. PR/C 6 JR. [1627/ m 20 BY d%& 4 M

ATTORNEY United States Patent ELECTRICAL CIRCUIT CONTROL SWITCH Osborne I. Price, Sn, deceased, late of Frederick, Md.,

by Osborne I. Price, Jr., executor, Frederick, Md., as-

signor to Magnetic Devices, Inc., Frederick, Md., a

corporation of Maryland Filed July 10, 1959, Ser. No. 826,182 3 Claims. (Cl. 200-6) The invention rel-ates broadly to electric circuit control switches and more particularly to an improved quick acting multiple-pole electrical switch.

One of the objects of the invention is to provide a switch mechanism having a multiplicity of poles confined in a small space having adequate insulation between adjacent parts and with all moving parts having such configurations that wear and fatigue resulting from numerous operations is minimized.

Another object of the invention is to provide a construction of electrical circuit control switch wherein the terminals to which the various stationary and moving electrical contacts are secured are arranged about the circumference of an annular insulator ring.

Another object of the invention is to provide a multiple-pole electrical switch wherein thefiexible springs to which the moving electrical contacts are attached are formed in such manner that their flexure per unit length is minimized, thereby reducing wear and fatigue and allowingthe switch to perform more efficiently and economically.

Still another object of the invention is to provide a multiple-pole electrical switch in which the angular displacement of the moving electrical contacts required for the opening and closing of mating pairs of stationary and moving electrical contacts is eifected by the operation of a cross-shaped actuator cam formed of electrical insulating material.

A further object of the invention is to provide a construction of multiple-pole electrical switch in which the particular formation of the flexible spring contact members allow a multiplicity of electrical contacts to be mounted in a small space.

Still a further object of the invention is to provide an electrical switch construction having a configuration suit able and adaptable for actuation either manually or electrically by an electrically operated actuating mechanism.

Other and further objects of the invention reside in the arrangement of the flexible spring contact members which allow the air space between open circuited pairs of mating contacts to be a maximum, thus enabling each set of contacts to control circuits of high voltage and high current .values as set forth more fully in the specification hereinafter following by reference to the accompanying drawings, in which:

FIG. 1 is a side elevational view showing a multiplicity of the electrical circuit control switch section of the invention mounted to an electrically operated actuator mechanism;

FIG. 2 is a side schematic view showing a multiplicity of the electrical circuit control switch sections of the invention ganged together to form a manually operated switch;

FIG. 3 is a horizontal sectional view taken substantially along line 3-3 of FIG. 1 and showing the actuator cam in one of its two extreme positions;

FIG. 4 is a view similar to FIG. 3 but showing the actuator cam in the other of its two extreme positions;

FIG. 5 is a transverse sectional view taken substantially on line 5-5 of FIG. 4, and particularly showing the manner in which two switch sections are fitted together;

FIG. 6 is a transverse sectional view taken substantially on line 6 -6 of FIG.. 4;

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FIG. 7 is a transverse sectional view taken substantially on line 7-7 of FIG. 4;

FIG. 8 is a top plan view of a movable contactor spring carrying a fiat contact used in the switch of the invention;

FIG. 9 is a side elevational view of the contactor spring shown in FIG. 8, looking in the direction of arrow A;

FIG. 10 is a cross-sectional view taken on line 10-10 of FIG. 8;

FIG. 11 is a schematic view, shown in perspective, of the centrally disposed operating shaft and particularly showing a method of returning the operating shaft to its original position after being rotated manually or by the electrical actuator;

FIG. 12 is a schematic view similar to FIG. 11 but shown an alternate method of returning the operating shaft to its original position;

FIG. 13 is a schematic view similar to FIGS. 11 and 12 and showing still another method of returning the operating shaft to its original position;

FIG. 14 is a top plan view of the actuator cam member used in the electrical circuit control switch of the invention;

FIG. 15 is a side elevational view of the actuator cam shown in FIG. 14;

FIG. 16 is a cross-sectional view taken on line 16-16 of FIG. 14;

FIG. 17 is a top plan view of a modified form of actuator cam for use in a modified form of electrical switch of the invention having more movable contactor springs than shown in the principal form of the invention; and

FIG. 18 is a top plan view of another modified form of actuator cam for use in a modified form of electrical switch of the invention having an odd number of poles and specifically utilized in a five pole double-throw switch.

This invention is directed to a compact construction of electrical circuit control switch containing a central cam member, carrying extended portions thereon, to which angular movement may be simultaneously imparted for simultaneously controlling the opening and closing of a multiplicity of contacts in a variety of circuit permutations and combinations.

A multiplicity of the switches of the invention may be assembled together to form individual switch sections of an overall larger switch. In this particular arrangement the central cam of each switch would be disposed on a common central operating shaft so that all sections of the switch would operate in unison. However the switch of the invention is utilized, it is designed for both manual and electrical actuation.

The electrical circuit control switch of the invention consists of a switch ring having symmetrically spaced radially extending terminal strips on one surface thereof carrying stationary contact'members on the ends thereof which terminate interiorly of the ring. Disposed on the opposite surface of the switch ring are a pair of movable contact terminal strips for each associated stationary contact terminal strip; the pair of terminal strips being symmetrically positioned one on each side of the stationary contact terminal strip and being radially disposed with one end thereof terminating interiorly of the switch ring and having 21 depending support thereon. A pair of flat resilient contact arms carrying contact points thereon constitute the movable contact members of the switch and are rigidly connected tothe depending supports carried by the pair of movable contact terminal strips such that the pair of contact points are biased to coact with the associated stationary contact member.

The resilient contact arms have an L-shaped configuration followed by a V-shaped bend providing an end for mounting to the depending supports. The opposite ends r 3 of the resilient contact arms-are disposed to coact with protruding lobes from a centrally disposed cam member secured to and rotatable in a clockwise and counterclockwise direction by a central operating shaft. The cam provides a protruding lobe for each stationary contact member which is disposed "opposite therefrom so as to coact with the terminating ends of the pair of resilient contact arms disposed to coact with the particular -sta-' tionary contact'mem'ber. Asthe cam is angularly displaced in a clockwise direction one movable resilient cont-act arm of each pair of resilient contact arms is moved into electrical contact with the associated stationary contact-member through its contact point while the other resilient contact armof each pair is moved out of electrical contact with the stationary contact member. In like manner, as the cam is angularly displaced in a counterclockwise direction theopposite resilient contact arms are moved into and out of electrical contact with the stationary-contact members such that electrical circuits connected with the associated terminal strips are opened and closed.

Referringto the drawingsin greater detail-each individual switch section, such as shown at 1-6 in FIG. 1,

the switch ring for supporting resilient contact arms I consists of a switch ring '7 constructed or molded of an insulation material, the switch ring of each section being separated and insulated from the adjacent switch ring by switch barrier 8 also constructed of an insulation rnate rial. The switch ring 7 and switch barrier 13 are of circular "construction with the diameter of the switch barrier being substantially greater than that of the switch ring so as to provide adequate insulation between the various "lead wires connected to the external terminals carried by the switch rings.

marks for the various'switch ring terminals. The switch barriers 8 are centrally apertured for the passage there through of a centrally disposed control shaft 13.

As shown in FIGS. 1 and 2 a multiplicity of the elcc-,

trical circuit control switches of the invention can be stacked to form an electric switch having many individual'sections such as sections 1-6 in FIG. 1. FIG. 1

shows six sections of the switch of the invention mounted on the top'of an electrically operated relay or actuator nism' 9, to secure the switch sections thereto; In FIG. 2

a multiplicityof the electrical circuit control switches of the'invention are shown ganged'togetherby bolts 14' to fo-rm'a manually operatedmulti-sectioned electrical circuit control switch. In this adaptation of the switch of the invention the centrally disposed control shaft 13 is manually manipulated to its two operating positions by control knob 15. The number of switch sections assembled together injeither electrical switch configurationis dependent upon the requirements of the electric circuits to be controlled. 7

FIGS. 3 and 4 illustrate the circular switch ring 7 carrying terminals 1623, symmetrically spaced with respect to each other, on the upper surface thereof consisting of radially extending strips having downwardly turned ends thereon, fitting into radially disposed grooves in the upper surface of'the insulation material of which the switch ring 7 is formed. The downwardly turned ends of the radially extending strips extend substantially parallel with the exterior side wall of switch ring 7 and are equipped with terminal studs 16a23a for attaching .control wires thereto from the electrical circuits to be controlled. The opposite'ends of the terminals 16-23 terminate interiorly of the switch ring and carry depending supports I6b- -23'b on the terminating ends thereof in close spatial relation with the interior side wall of a Thegreater diameter of the" switch barrier also provides space for identifying 24-31, respectively.

Disposed in radial grooves on the lower surface of the switch ring 7, are terminals 3235 consisting of radially extending strips having upwardly depending ends thereon extending substantially parallel with the exterior side wall of the switch ring. The upwardly depending ends of the terminals 32-35 carry terminal studs 32a-35a for eliecting electrical connections thereto from the controlled circuits. The opposite ends of terminals 32-35 terminate interiorly of the switch ring and carry depending contact bars 32b-35b thereon at points further removed from the interior side wall of the switch ring: than the position of the depending supports 16b23 b. The contact bars Mb-35b and supports 16b-23b are disposed on axes parallel with the central axis of the operating shaft 13. Each terminal HS-23 and 32-35 includes an 'instru-ck projection l6c23c and 320-4150 extending from the lower surface thereof for mating with a corresponding depression in the re- I spe'ctive groove for securing the terminals to the switch ring.

Clearance grooves 7 ring center axis on the external ring'are disposed beneath the stud side surface of the switch positions of terminal studs Ida-23a and Ma -3 5a on the dependingends of terminals 1623 and 32- 35. The purpose of these grooves 7' is to allow' clearance between the terminal studs and the switch ring when the terminal studs are threaded through the depending ends of their-respective terminal members. They also allow a morecompact switch'design since the depending ends of the terminal members can be disposed substantially flush with the switch ring external side wall since the grooves 7 dis? posed beneath the depending ends provide the necessary stud clearance thus eliminating the need for spacing between thedepending terminal ends and the switch ring side wallwhich adds to the overall switch diameter.

ing terminals, mediate resilient arms posed intermediate resilient arms 26 and 27, contact bar 34b is disposed intermediate resilient arms 28 and 29,

and contact bar 35b is disposed intermediate resilient arms 30and 31. Resilient contact arms 2 4-31 con stitute the movableelectrical contacts of the switch" and, as illustrated more clearly by resilient arm 31 in FIGS.

840, are of substantially L-shaped configuratio'n'in the unloaded state and are constructed of an electrically conductive spring material such as phosphor-bronze, 'beryl- H lium-cop-per, nickel-silver, etc. The short arm'of'the L-shaped configuration of each resilient arm has'a'n ex tension bent slightlyback 'up'on'itself to form a V-shaped bend with a hook arrangement on the end thereof for engaging its corresponding depending support 1 6b-'23b.

The resilient contact arms 24+31are normally'soldered' to supports Mb-23b to insure a positiveelectrical'con nection therebetween. The combined configuration of the flat resilient contact arms having an L-shaped bend followed by a V-shaped'bend minimizes the s izure per unit length of the resilient contact'arms and thus pro vides long operating life since wear and fatigue aremi'nimized. The long arm of the L-shaped configuration ofeach resilient contact arm 24-'31 carries a contact ineni ber designated at 24a-31a, respectively, havinga pr'o trusion extending throughits corresponding resilient arm and an accompanying reinforcing washer 36 at a point L slightly removed from. the end of the long arm" and secured thereto by having the protrusion peaned over. The particular configuration of the resilient'contact arm's" that constitute the moving contactsof the switclialldw'si the air-space between open circuited 'pairs of mating con disposed axially with the switch" tacts to be a maximum, thus enabling each set of associated contacts to close and open electrical circuits of high voltage and high current values. This particular configuration of the resilient spring contact arms also allows a multiplicity of electrical contacts to be mounted in a small space.

When the resilient contact arms 2431 are assembled into the switch of the invention the short arm of the L-shaped configuration is compressed against the interio side wall of the switch ring 7, thus decreasing the angle of the V-shaped bend and the long arm of the L is slightly spring-loaded, back upon the short arm forming an acute angle therebetween, since the terminating end of the long arm of each resilient contact arm is arranged for bearing contact with a corresponding extending lobe of the actuator cam 37. The contact members 24a-31a on resilient arms 24-31 are positioned to coact with contact bars 32b-35b as the actuator cam 37 is rotated in its operative arc by shaft 13, such that, contacts 24a and 25a coact and alternately make electrical contact with contact bar 32b, contacts 260 and 27a coact and alternately make electrical contact with contact bar 33b, contacts 28a and 29a coact and alternately make electrical contact with contact bar 34!), and contacts 30a and 31a coact and alternately make electrical contact with contact bar 35b.

The angular displacement of the movable resilient contact arms required for the opening and closing of the mating pairs of stationary contact bar and moving elec trical contacts is effected by the operation of a crossshaped actuator cam 37 formed from an electrical insulating material, such as nylon. As an example, the angular displacement of the cross-shaped actuator cam 37 in a clockwise or counterclockwise direction from the central position for opening and closing the mating pairs of contacts is approximately 28 degrees. This provides an air gap of approximately 0.060 inch between open switch contacts. 1

The cross-shaped actuator cam in the principal form of the invention, as shown in FIGS. 3, 4 and 14, carries four lobe portions 37a, 37b, 37c and 37d positioned around and extending from a central actuator cam portion at 90 from each other. The opposite side surfaces of each lobe extend inwardly toward the center of the cam at small acute angles with the lobe radial center axis to form efficient bearing surfaces for the end portions of the associated resilient contact arms and allow the contacts carried by the resilient contact arms to be opened a substantial distance when the cam is rotated by shaft 13. Each lobe portion of the actuator cam is positioned opposite a contact bar member, intermediate the pair of resilient contact arms disposed to'coact with the particular contact bar member as seen in FIGS. 3 and 4. The actuator cam is secured to the operating shaft 13 so as to rotate therewith through a central aperture 38 in the cam having the same cross-section as the central operating shaft 13. When several of the switches of the invention are ganged together to form a large switch having several sections, the actuator cam of each section is secured to the common central operating shaft so that the cams of each switch section move in unison with each other and the center shaft.

As previously mentioned the configuration of the electrical switch of the invention is suitable for actuation either manually or by an electrically operated actuating mechanism such as a relay. If the switch is operated manually, a detent mechanism such as a detented flat spring plate acting in combination with a ball locking member could be used to hold the shaft 13 and the actuator cam 37in one of two positions. Another arrange ment could provide a coil spring or pair of coil springs such as shown at 39 in FIG. 11, working against the manually applied operating torque 40 to provide a restoring torque to shaft 13. With this arrangement the switch could be used to provide momentary closure or opening of electrical circuits as long as operating torque is supplied to the center shaft, and the coil springs would return the shaft and actuator cam to their original position as soon as the applied torque 40 was released. The arrangement shown in FIG. 11 can also be utilized when the switch is actuated by an electrical actuating mechanism. When thus used the member 41 secured to shaft 13 and to which springs 39 are attached becomes the rotor of an electrical actuator and the combination of the switch and actuating mechanism becomes an elec trical relay suitable for control of numerous electrical circuits. FIGS. 12 and 13 show arrangements of flat spring 42 and wire-loop springs 43 which may be used for returning the actuator cam and operating shaft to their original position once the torque applied to the shaft by an electrical actuator through rotor 41 is released. Thus FIGS. 11-13 suggest various methods by which the central cam actuator shaft 13 may be biased to return it to its original position once an operating torque has been released. These methods are only shown by way of illustration and are not meant to be limiting vupon the many other methods of obtaining desired shaft positions.

As previously mentioned, the switch of the invention is a two-position switch. The switch is shown in one of its two positions in FIG. 3, while in FIG. 4 the switch is shown oriented into the opposite position. In FIG. 3 the cam 37 is shown rotated clockwise such that the lobes carried by said cam have opened the electrical contact between the stationary contacts bars 32b and 33b, 34b and 35b and the associated contact members 25a, 27a, 29a and 31a carried by the movable resilient contact arms 25, 27, 29 and 31, respectively. This is accomplished by the fiexure of the resilient contact arms 25, 27, 29 and 31 away from the stationary electrical contacts due to the force applied to the end portion of the resilient arms by the protruding cam lobes. Each resilient contact arm is actually a flexible lever member with the fulcrum on one end thereof and the load constituted by the contact member intermediate the fulcrum and the opposite end of the arm where the moving force is applied. Since the resilient contact arms are biased toward the stationary contact bars as the cam rotates clockwise, the resilient contact arms 24, 26, 28 and 30 move the contact members 240, 26a, 28a and 30a carried thereon into electrical bearing contact with the stationary contact bars 32b, 33b, 34b and 35b, respectively. Thus in this switch position, electrical circuits are closed between terminals 1632, 18-33, 2034 and 2235, and electrical circuits are opened between terminals 1732, 19-33, 21-34 and 2'3-35.

In FIG. 4 the cam 37 is shown angularly displaced in the counterclockwise direction to effect circuit closures between terminals 17-32, 19-33, 21-34, and 23- 35 and open circuits between terminals 1632, 1833, 2034 and 22-35. As the cam is rotated counterclockwise it removes the displacing force from the resilient contact arms 25, 27, 29 and 31 and as these contact arms are biased toward the stationary contact bars 32b, 33b, 34b and 35b respectively, they automatically move the contact members 25a, 27a, 29a and 31a carried there on into electrical contact with the respective stationary contacts. Concurrently, the cam lobes apply a displacing force to resilient contact arms 24, 26, 28 and 30 which opens the electrical contact between the contact members 24a, 25a, 28a and 30a carried thereon and the respective stationary contact bars.

In FIG. 17 a modified actuator cam 44 is shown carrying six lobe portions thereon for utilization in a modified form of the switch of the invention which constitutes a six pole, double-throw switch. The cam and switch can be designed to carry any desired number of lobes and poles, respectively, as long as the number is maintained While the invention has been described in one of its preferred embodiments it is realized that modifications may be made, and it is to be understood that no limita tions upon the invention are-intended other than those which may be imposed by the scope of the appended claims.

What is claimed as new and is desired to be secured by Letters Patent of the United States is as follows:

1. A multiple circuit control switch comprising an annular body of insulating material, a plurality of circumferentially' spaced terminal elements secured to the top face of said annular body and projecting radially inwardly of the bore of said body, a corresponding number of pin elements dependently secured to said terminal elements inwardly of said bore, a corresponding number of spring contact arms having substantially radial portions and portions extending circumferentially of said bore and engageable with the bore, said arm portions being disposed at'near right angles to each other, said radial portions each having a free end, extensions carried by the circumferential portions of said contact arms and diverging therefrom and secured to said depending pin elements inwardly of said bore, contacts carried by said radial portions of said arms intermediate the ends of said radial portions, additional terminal elements secured to the lower face of said annular body between adjacent pairs of the first named terminal elements and projecting radially inwardly'of said bore of the annular body and inwardly of said depending pin elements and spaced from the latter, upstanding stationary pin contact elements secured to the second named terminal elements near their inner ends and disposed between said contacts carried by the radial por-.

tions of said contact arms, a rotary actuator shaft for said contact arms extending axially through said bore centrally thereof, and a cam actuator mounted upon, said shaft to turn therewith and including a plurality of circumferentially equidistantly spaced radial projections corresponda r ing in number to-the pairs of said arms, said radial projections being wedge-shaped and including radial inwardly converging side faces and outergenerally circumferential faces defining outercorners'on said-projections, the side faces and outer corners of the radial projections being engageable between the free ends of the radial portions of each pair of said arms radially'inwardly of-saidcontacts carried by said arms, whereby rotation of said-shaft in either direction causes the side faces and outer corners or said radial projections to engage the radial portion of one arm of each pair of arms for disengaging the contact 7 of said arm from the adjacent stationary 'pin contact element, said arms'being resiliently tensioned to normally maintain said contacts of the arms engaged with said stationary pin contact elements 2. A multiple circuit control switch according to claim l, and wherein a plurality of said annular bodies of insulating material are arranged in stacked concentric relation, in sulating plates mounted between each pair of said stacked annular bodies and projecting radially beyond the peripheries of said bodies and radially beyond said terminal elements carried by the bodies, and axially extending bolt means engageablethrough all of said bodies and plates for securing the same together in stacked relation.

3. A multiple circuit control switch according to claim 1, and vwherein said annular body of insulating material is provided in its periphery with a plurality of circumferentially spaced recesses adjacent said terminal elements,

depending extensions secured to theouter ends of the I first named terminal elements adjacent-some of said recesses, upturned extensions carried by the outer ends of the second named terminal elements adjacent the other recesses of said plurality of recesses, andradial set screws adjustably secured'to all-of said terminal element exten sions and engageable within said recesses, the first named terminal elements having interlocking engagement with the top face of said annular body and the second named terminal elements havinginterlocking engagement with the bottom face of'saidbody.

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Coleman Se t. 12; 1918 2,387,055 Bryant s Oct. 16,1945 2,795,658 Ward-' June 11, 1957 FOREIGN PATENTS 158,994

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